Method of preserving edible liquids



Feb. 28, 1950 v A. FRANKLIN 294999243 METHOD OF PRESERVING EDIBLE pmums Filed Sept. 19, 1945 2 Sheets-Sheet l INVENTOR. Alberia Franklin Feb. 28, 1950 A. FRANKLIN METHOD OF PRESERVING EDIBLE LIQUIDS 2 Sheets-Sheet "2 Filed Sept. 19, 1945 INVENTOR. Albefio ifaznlflul ATTORNEY Patented Feb. 28, 1950 UNITED STATES PATENT OFFICE- METHOD OF PRESERVING EDIBLE LIQUIDS Alberto Franklin, Caracas, Venezuela Application September 19, 1945, Serial No. 617,328

1 Claim. 1

It is a primary object of this invention to provide a process for the preservation of foods in liquid form, which process will be effective without the use of refrigeration or any of the usual chemical preservatives.

It is a further object of this. invention to provide a method by which bacterial action in liquid foods may be inhibited without recourse either to chemical or (in most cases) thermal methods.

It is a further object of this invention to preserve foods in liquid form without chemical or other change during the period of treatment or preservation. a

The above and other objects will be made clear from the following detailed description taken in connection with the annexed drawings in which:

Figure 1 is a schematic diagram of an apparatus for the treatment of milk for short term preservation or for the long term preservation of fruit and vegetable juices; and

Figure 2 is a similar diagram of an apparatus for the treatment of cane juice.

Any treatment which will inhibit or retard the action of bacteria will act, to a degree, as a food preservative. For example, freezing retards such action. Pasteurization, on the other hand, by destroying large relative numbers of bacteria, similarly acts to retard the action, though in a thermal sense it is the opposite of freezing. Boiling is merely an extreme of pasteurization, and, by the use of pressure, may result in the annihilation of all bacteria. Disinfection, or antisepsis will accomplish the same result, but as a method of preserving foods, suffers from the disadvantage that the antiseptic r disinfectant agent may be toxic at worst, or, at best may alter the flavor of the food.

The present invention contemplates a treatment of food in liquid form which will preserve such food for substantial periods without contributing the slightest toxicity, and wholly Without chemical alteration of the food, but which, at the same time, will not alter the chemical properties of the food, nor its flavor. While this process is described with particular referenceto the treatment of milk, fruit and cane juices and beer, it is applicable to vegetabl juices, soups, and, in general, to any food so far in liquid form as to permit a uniform distribution of a preserving medium throughout the mass.

Referring now to Fig. 1, there is shown a tank I0, preferably cylindrical to withstand internal pressure, s'urroundedby a jacket I2. The tank I0 is-closed at one'end by a bottom l4". shown 55 as concave, but which may, if desired, be convex, and having at the other end a removable, spheroidal cover IS. The cover [6 is secured to the tank Ill by means of clamping bolts l8, or other suitable means. The center of the cover it is penetrated by a processing pipe 20 which extends downwardly adjacent the bottom [4 of the tank I. The pipe 20 has, at its upper end, a pressure control valve 22 to which is connected a pipe or hose 24.

Also mounted in the cover I6 is a thermometer 26, a pressure guage 28 and a bleeder valve 30. A pressure guage 32 and a steam valve 34 are mounted in the top 36 of the jacket l2. A steam outlet 38 is mounted in the lower portion of the jacket [2 and passes through a valve 40 to an exhaust pipe 42. A drainage pipe 44 penetrates the jacket i2 and enters the tank Ill. The

drainage pipe 44 connects with a valve 46 which in turn is connected to a drainage outlet 48.

The pressure pipe or hose 24, at the end opposite the valve 22 connects to a regulator valve 50 having the conventional tank and line pressure guages respectively indicated as 52 and 54. The regulator valve 50 is connected to a gas tank 56 having at its head end 58 a conventional shutoif valve 60. In cases, described hereinafter, where treatment with two different gases is desired, a second gas tank 62 is provided. In such cases the regulator valve may be alternately con nected to either of the tanks 56 or 62. Obviously a permanent pipe and dual connections may be provided if desired. If this is the case, tank 62 will have its own regulator valve and guages, similar to 50, 52 and 54 and the valve will be connected to a Tee in the line 24, while a shutoff valve may be provided in the line 24 between the Tee and the tank 56.

The apparatus just described is used in the treatment of fresh, whole milk, when it is desired to preserve the milk for a period of six to about ten days, as follows:

Fresh, whole milk (skimmed milk is, obviously, equally usable) is run into the tank I!) while the cover I6 is removed. The tank I0 is, of

course, sterilized by the use of steam or other suitable means before the milk is supplied. When the tank I0 is filled approximately to the level of the cover |6,'the cover is applied and is secured by means of the bolts I8. The bleeder valve 30 is opened and the valves 22 and 50 are operated to bring about a flow of ordinary molecular oxygen from the tank 56, through the hose 24 and the. pipe 20 through the milk .in the tank 10. The oxygen bubbles upwardly through the milk and drives before it the air entrapped in the cover I6. The air and oxygen pass through the bleeder valve 30.

When substantially pure oxygen is flowing through the bleeder valve 30, and this may be detected by many conventional and simple tests, the valve 30 is closed and the flow of oxygen through the pipe 20 is continued until the internal pressure within the tank IE3 approximates six atmospheres. The valves'ZZ landfill are-then set merelyto maintain this pressure approximately stable for a period of about four hours. Valves 22 and 5B are then closed and the bleeder valve 30 is opened to relieve the internal;pressure in the tank II] until it is equal to about three atmospheres. Under this-latterpress'ure,

for the particular plant, and no one skilled in the art should experience difiiculty in determining the optimum conditions for his particular operation.

When the material to be treated is substantially a true solution as in cane juice, or colloidal as in the case of milk, the treatments above described may be followed rather precisely. In certain fruit juices there are, however, relaitively large particles present and in the case of certain vegetable juices the bacterial agents which promote decay are particularly obstinate. "When either or both of these conditions are enthe milk may be preserved:fortfromssixrto ten I days. It is, of course, possible either to main-' tain the three atmosphere pressure in the "tank III, or in an auxiliary storage tank, or tanks, or "to :bottle :the milk under that pressure.

:.The important "aspect :zof the :treatment just described is that the -molecular:oxygenzusedais tonly' veryisliglitly soluble-in 'the liquidwhaserof zthexmilk, hence aupon ultimate relieft o:atmosrpheric pressureuvill. leave" the milk 1 without. anialyzable trace .of .its presence. Moreover, :the oxygen-"being in molecular'form has :nottendency itozcombine with any element of .the1milk,1.and, therefore, leaves the milk chemically unchanged. The :temperature of 'the m'ilkiduring the :period rofcstorageiis immaterial,pbothstoragezand the i'treatment'beingcarried outaat roomtemperatures. .zZAs .a -result,:there is no impairmentpfi the :chem- :ical, :nutritional :fiavor or :other :qualities .of the 1 '1,mi1k,,"2,SiS"the case with pasteurization.

'When it is desired to preserve. milkior periods .isubstantially longer .thanten days, that:is,'of {three months or;more,v steps. additional to, those above described should'be interpolated. For. long. i'term: preservation, .the valve i5El islfirst connect- "ed :to the tank-252, containing carbon :dioxide 'g8.S -(C.Oz) ,.:.an'dathe :process :of filling-the tank IIU, .securing .the cover 16, admitting the gas, and :bringing :the ;:pressure up :to v-approxirnately :sx atmospheres ;is :repeated. .The :six atmosphere ,pressure is maintained .forapproximately four hours. The :"pressure .is then :relieved, by means :of .the bleeder valve '30, back :to atmospheric.

'With :the V&1V8-139 open, steamisradmitted to 'thejacket l2 until the'temperatureofthe milk "within the tank It .is raised to approximately .270 .Fdegrees centigrade. Both atmospheric pressure and the seventy edegree temperature are :then :maintained for 1 from forty-five minutes :to --an hour. 'E'Ihe .result 1 is Ito drive from the :milk ;substantially all of .the C02. The valve-501s then disconnected from the-CO2 tank-62 and :connected to the oxygen tankifi. The process previously described for short-term .preservation is then"repeated,.i. e., bringing the-internal pressure in tank I0 to six'atmospheres with-:oxygen. .maintaining the pressure. for approximately. four chours; then .bleeding :to .three: atmospheres and gstoringat:that pressure. The steam mayibeecut ,Offi'WhBll the, oxygen treatment begins, since from that point-ion, temperature: isimmaterial.

,iTor 'fruit and vegetable juices :the treatment, "whether for short or long i term preservation, .-is substantially thesamepas the above described :treatment or. the-short term preservation1of.milk. For any;particular juice, and for any; particular .tperiodpof storagezof such .ijuice, there may be minoravariationstofJaime andgpressureirom those zin'dicated. ,iIhese, however, rare best determined countered, thercombined carbon dioxide and oxygen treatment should be resorted to and the -iriterme'diate heat treatment should be increased -..either-.by raisingtthe temperature, or increasing the time, or both.

Fig? 2- illustrates particularly the adaptation of this process to the preservation of sugar cane tjuice' Ihe' crush T130115 met :a "conventional sugar mill are Iindicated rat I I10. "l'lhe ijuiceiextracted :by :the rolls EIBI) zfiows :to La :collecting .tank I102. .Juice is :removed ifrom the :collecting tank H102 by means of a pump'lifl l and-is;,passedi.through :a filter' lllli thence to astreatment tank: I08. Db- "viously, :juice 1 must .be permitted to accumulate 'in thepollecting tankI'UZ untilithereiis assumicient quantity -to:filluthe treatmentctank M18. :The tank IE8 is then filled relatively quicklybysmeans tof theapump H14. 'A bleeder valve llllinz-the'itop I I 210i the:tank: I 08iis thenzcpenedi and oX-ygenlis 'J-supplied 1' from 11a pressure tank :I H :through ra treatment pipe H6 in all respectsiasspreviously "described. When a the -.=air zhas :been :driven 'JOllt, :the: bleeder valvev I I 01:15 closed-and: pressure with- ;in .the ,tank I08 :brought to 1 about: sixatmospheres. The rpressurezmay'be readron-ra Loonventional ,gauge 2H8 rand iiS :maintained .for ca :period=tof:about.;.fourrhours. The bleeder valve H0 is then opened,=..but:inithisqcase *reliefzisback ztonatmospheric pressure. .lIhe treated juice is then removed from the :tank 403 -'by;means/of a :pump I20. The 1, pump :l-ZO supplies the .;juice to a clarifier I22. A second pump I 24 .removes "the juice :from :the zclarifier I22 .and forces -.it throughafilter I26 athence vto-asecond clarifier I28. A pump 1'30 :removes the juiceyfrom the second clarifier I28, ;passes a. it through an addi- .tionalxfilter l'32' andzintoxa bottling machine L34. With the exception of the treatment ;tank 1-08, .all of the apparatusillustrated Fig. 2'is conventional Land 'rnot :here "disclosed in -.detail. When carrying out the .method as :disclosed in Fig. 2,.it will'jfrequently beifoundrthat the output ;of the crush .rolls I00 .is --greater than can :be accommodated 4 by va single .treatment unitcomprising the treatment \tank 18 and: its associated clarifiersvandfilters. :Insuchcase, a'plu- .rality of treatment :units may -.be arranged .in parallelpto take-.the-outputof .the crushlrolls I00. iwhilesthereiis disclosed:hereincertain specific .detailscof time, temperature, .and pressure, and :certainsspecifimarrangements..of;parts. for=.carrying out processea;it:.:is nQtLintendedJto limitnthis .inventionsto thedetails ofzthev disclosure, butonly as set ,i'iorth in athe ssub-joined --.claim which :is .to vbe broadlyci'nristrued.

;.I..claim: I

'A processof preserving raw, .untreated edible liquids .comprising: ;.-placingra: body-..of suchliquid :in :a sterile, =.closed container .at atmospheric .pressure; injecting scarhon cdioxide :adjacent the :hottom 10f sai'dmontainemrmaintaining .the prea 7 sure subs an iall a iatmnsnhe aie i l fat e etmosphere abo'y egzthe liquid in said container is substantially pure carbon dioxide; then injecting additional carbon idioxide to bring the pressure within the container to not substantially less than 6 atmospheres; maintaining said pressure stable for not ubstantially less than 4 hours; then relieving ig sa -pressure to atmospheric while simultaneously eating said liquid to a temperature at which carbon dioxide is substantially n t atmospheric pressure; thereupon discont n said heating and simultaneously injecting, "Qlecular oxygen adjacent the tainer; maintaining the pressure in said. J ner substantially at atmospheric by bleed'ng; mm the top of the container until the atmosphere in the container above the liquid is substantially pure oxygen; then injecting additional oxygen to bring the pressure within the containerfto not substantially less than 6 atmospheres; maintaining said pressure stable for not substantially less than 4 hours; then relieving said pressure to not substantially less than 3 atmospheres and storing said liquid under the latter pressure.

ALBERTO FRANKLIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 994,641 Hansen June 6, 1911 1,017,144 Gironcoli Feb. 13, 1912 1,103,920 Walker July 14, 1914 1,250,079 Bart Dec. 11, 1917 1,270,698 Cofiman June 25, 1918 1,305,244 Bacon June 3, 19 9 1,649,127 Rector Nov. 15, 9 7 1,725,956 Cleveland Aug. 27, 1929 2,361,640 McKinnis Oct. 31, 1944 

